WASHINGTON —  An FBI computer system that quickly screens gun buyers' backgrounds for criminal activity crashed several times over the past two days, officials said Monday.

At times, the National Instant Criminal Background Check System was on the blink for up to a half-hour on Sunday and Monday _ potentially allowing buyers to purchase firearms without being screened if sellers gave up on making the required check.

The computer crash was blamed on a technical glitch that was being worked on Monday evening, said FBI spokesman Paul Bresson. "It's a performance issue that we've never encountered before," he said

It was unclear when the glitch would be fixed.

The system, located in Clarksburg, W.Va., generally receives between 30,000 and 50,000 requests for background checks on a daily basis, peaking on the weekends, Bresson said. It usually processes the requests within 30 minutes.

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